COPD

[with gratitude and thanks to Dr. Stephen Rennard – pulmonary specialist, scientist and professor – he sent me research articles, a book chapter and some email clarifications]

I have worked on this post for some time now. I hope that I can share the important characteristics of the disease, its causes, how it is diagnosed, prevalence, treatment guidelines and maybe USA mortality and morbidity statistics.

There are still things that I do not understand – mostly because of the highly technical material I read which did increase my vocabulary when it did not overwhelm me. There came a point when I had to admit, I really did NOT have to know ALL of those details to do my job or write this blog.

I do think that this was somewhat harder to process than the information related to heart disease and smoking which I shared back in February. With regard to the heart, there is endothelial damage and with the lungs it is mostly epithelial. This helps me to recognize the difference better – epithelial is tissue and organ cells – like the lungs and endothelial has to do with blood vessels!

So let me begin:

COPD stands for Chronic Obstructive Pulmonary Disease and is included in the CLRD category of the leading causes of death. It is the fourth leading cause of death in the USA after heart disease, cancer and stroke. In the world, it can be THE leading cause of death in low income countries.

The established definition of COPD is as follows:
Chronic Obstructive Pulmonary Disease (COPD) is a preventable and treatable disease with some significant extrapulmonary effects that may contribute to the severity in individual patients. Its pulmonary component is characterized by airflow limitation that is not fully reversible. The airflow limitation is usually progressive and associated with an abnormal inflammatory response of the lung to noxious particles and gases. (book chapter -see end notes)

There are two main diseases in this disease categorization – chronic bronchitis and emphysema. I have at times been confused with regard to where asthma fits in. The main difference between COPD and asthma is irreversibility. Both diseases involve an obstructed airway, but most often asthma will respond with a complete reversal with a medicine referred to as a bronchodilator. In other words, a medicine that opens the airways. Probably because, in mild to moderate asthma, the airways are blocked from muscle spasms, not damage and once those passage ways are relaxed, normal breathing can resume.

There is a respected global non profit organization or consortium that includes the USA’s NHLBI and NHI as well as the WHO. The entity is called GOLD for Global Initiative for Chronic Obstructive Lung Disease. GOLD has clinical practice guideline for identifying, preventing and treating COPD. Most of the research literature on COPD will refer to the GOLD standards for identification and treatment. For that reason, they should be noted. These signs and symptoms below are clinical indicators of disease, however, it is protocol that a person with them be considered as having COPD with a lung function test to confirm. Significantly, a person who does not have the signs but has been exposed to risk factors such as chemicals, dust and tobacco smoke should also be evaluated.

The signs are:
Shortness of breath or feelings of breathlessness often referred to as dyspnea
Chronic cough (may come and go and may not produce any phlegm)
Chronic sputum production (any time this occurs it is a WARNING for COPD)
The risk factors are:
Tobacco smoke (the number one cause of COPD and possibly the cause of 50% of all cases)
Exposure to dust and chemicals on the job (occupational exposure)
Smoke from home cooking or heating, especially in some countries where biomass fuels, such as coal, wood, straw and animal dung are used.
Risks that may be less common or more likely to be synergistic include:
Gender, genes, infections, outdoor air pollution, asthma and being poor or living in an impoverished nation.

The lung function test and the parameters for diagnosis are spirometry and FEV1/FVC.
Let me explain. The spirometer is a device that the patient blows into and it provides the clinician with a reading. There are specifics on how one inhales and exhales or blows for the test, but they are not necessary here. The letters stand for Forced Expired Volume in one second and Forced Vital Capacity. COPD as defined by the GOLD standards, has four stages. The stages are based on the FEV1/FVC score. All stages have FEV1/FVC less than .70 and then they have an additional predicted value of the FEV1 which is diagnostic.
1- Mild - the persons FEV1 is 80% or more of what similar persons (without disease) would score. There may be no other signs and a person may not complain. It is very important then that providers know about the risk factors and DO use the spirometer in said patients to catch the disease early and treat accordingly.
2- Moderate- the FEV1 is now between 50 and 80 % of predicted and shortness of breath is more common, especially when the person is active. There may be cough with sputum or discharge and this is when a patient often seeks help.
3- Severe – the patient’s air flow is limited further and the value is below 50% of predicted but above 30%. Now a person’s health quality and activities of daily living are adversely affected.
4- Very severe- the patient has significant obstruction and a predicted FEV1 of less than 30 or less than 50 with other complications, such as acute respiratory failure. This stage can have many exacerbations or worsening for the person and can be life threatening.

So as you can see, the spirometry is the standard method for diagnosing COPD and for staging its course. There are other diagnostic tests and imaging that can be used to get more details on disease. Those can be explored elsewhere.

The absolute most important thing to be done at ANY stage and immediately is to STOP the exposure to the toxicant. In other words, stop smoking. In the USA and several other countries work exposures are limited – for instance, some chemicals are banned and some regulations require masks and ventilation. Coal miners are a group that continues to have work exposure that can lead to COPD as well as Black Lung. In some countries, however, no occupational safe guards exists and there are no other options for heating and cooking – this is a significant health threat to those individuals. Outdoor pollution is less a threat to cause COPD, but may lead to exacerbations of illness.

Do NOTE: We all lose a certain amount of our lung function as we age and thus the FEV1 predicted value difference can show the acceleration especially in smokers. Smoking cessation (quitting) can prevent progression of emphysema only in its earliest stages. But cessation always improves treatment outcomes. A person who quits smoking by age 30, in at least one clinical trial, shows no difference in lung aging than a healthy non smoker! (if they do not already have disease)

Treatment includes oral medications,(pills or inhalations) and most often does not include nebulizors. The standard pharmacotherapy includes bronchodilators of two types as well as long and short acting ones. In other words, a person can take a daily formulation of a bronchodilator and then use a short acting one as needed or in crisis. Other meds used, especially in later stages, include inhaled glucocorticosteroids and then systemic steroids. Treatment can include the use of oxygen therapy as well – as needed or at night, or continuous. Oxygen use is based on the person’s oxygen and carbon dioxide levels. People with COPD are especially encouraged to be vaccinated against the flu and less strongly pneumonia. Lung volume reduction, lung transplants and other invasive surgeries can also be performed.

____________ A little pause to note that I have far more information that is needed for a blog post – And I have three more things to cover______________

Prevalence
Disease type
Exercise Therapy

Prevalence is the term used to describe the number of persons living with a disease at a certain time point – like now or when the statistic was last available. This is different than incidence, which is the number of new cases, usually offered by year or projected into a decade. The prevalence will differ by nation. I have to say that there is a concern in the scientific community that the prevalence is grossly UNDER estimated based on the fact that spirometry is NOT used and that many persons with the disease are not unidentified at the earlier stages. For that reason it is better to tell you the differences as offered in a Lancet journal article forwarded to me by Dr. Rennard. The chart offered there has cases per 100,000 persons and includes only stage 2 or higher COPD. There is a gender difference sometimes extreme sometimes slight. The highest prevalence is noted in South Africa which is probably related to home fuels and the lowest is in Mexico which I speculate has a low smoking rate. The USA is center left – i.e. closer to South Africa than Mexico and for some reason the UK is not on that chart. The USA is one of only a handful of countries where the rates in women is higher than men. For a look into the mortality rates of COPD in the USA please view this MMWR from the CDC.

The differences between chronic bronchitis and emphysema are significant. I am afraid that if I try to offer much detail I may make mistakes – and I have read and read and read in an attempt to grasp this fully.

Chronic bronchitis has to do with a buildup of mucus in the lungs. Certain cells in the tissue will react to irritants and cause mucus secretion which under normal circumstances will help to clear out toxic or irritating substances. The bronchial tubes swell also and this mucus and swelling makes the airways smaller. This is now the lungs are obstructed. Chronic bronchitis is the type of COPD that is associated with coughing and sputum. It can also be exacerbated by a virus or bacterial infection.

Emphysema is noted for being the disease in which the alveoli or little air sacs are destroyed. There is a lot that goes on with both diseases that leads to oxidant stress, inflammation, scarring and dysfunction. As the lungs lose elasticity in emphysema and air sacs are destroyed, the lungs have more volume – but that is a negative thing. There is a treatment, rather invasive, to remove the damaged lung and it is called Lung Volume Reduction Surgery. People with emphysema sometimes describe their breathlessness as feeling like they are drowning. The lungs do not fully expand or relax and normal breathing is compromised.

There are treatment options beyond the medications or procedures listed above which include controlled coughing and controlled breathing – these are actual physical techniques learned by the patient.

Of utmost important with regard to health quality is returning the patient to a level of functioning that is independent and retains quality. In that regard, as indicated in the book chapter written by Shapiro, Reilly and Rennard , “exercise conditioning is the single most important aspect of rehabilitation and has been repeatedly shown to improve exercise capacity and endurance….as with any exercise program, gains in conditioning are lost if the exercise program is stopped.” Read that last part again people – that applies to ALL of us.

There is so much more to know about this disease. You can take this free course on it if you like – you can visit the website of GOLD – you can review the articles I have read and you can view this website recommended by Dr. Rennard.

The articles are:
The natural history of chronic airflow obstruction revisited. Am J Crit Care Med Vol 180 pp. 3-10, 2009
At A Glance outpatient management resource for COPD. GOLD Report 2009.
COPD: the dangerous underestimate of 15%. The Lancet. April 15,2006.
Global burden of COPD: risk factors, prevalence and future trends. The Lancet, Vol 370. September 1, 2007.
Chapter 39 (book title unknown -personal correspondence) Chronic Bronchitis and Emphysema, Shapiro, Reilly and Rennard. Current.